1. Field of the Invention
The present invention relates to an optical device, for example, a pair of binoculars, which is provided with a correcting function for trembling of a focused image.
2. Description of the Related Art
Conventionally, there is known an optical device, such as a pair of binoculars, which is provided with a correcting function for trembling of a focused image. For example, an image tremble correcting mechanism is disclosed in U.S. Pat. No. 5,917,653. In the image tremble correcting mechanism, correcting optical. systems are driven two-dimensionally on a plane perpendicular to optical axes of the correcting optical systems.
Such an image tremble correcting mechanism is provided with a frame holding the correcting optical systems. A portion of this frame, at which a driving force is added, and a leading member which leads the frame in a predetermined direction on the plans, are spaced. Namely, a distance between the portion of the frame and the leading member is large. Accordingly, a moment of force, the rotational axis of which is the portion at which the driving force is added, is generated, when the frame is driven. Accordingly, the driving amount of the frame corresponding to the added driving force can not be determined. Namely, the driving of the correcting optical systems is unable to be accurately controlled.
Further, each time the frame is driven, unexpected forces are added to each member of the correcting mechanism, due to the aforementioned moment of force. Accordingly, the frame can not be driven smoothly, and portions of each member, which come into contact with other members due to the unexpected forces, are worn away.